随着交通环境的不断变化，部分城市道路平面交叉口的设计已不能满足交通现状，无法承受现有交通流负荷，使交叉口的运行效率低下。基于最优化理论和城市道路交叉口渠化设计准则，通过对交叉口的通行能力、饱和度以及服务水平进行最优量化分析，筛选最优信号周期，匹配最佳优化方案，建立交叉口道路通行能力模型，并以成都市敬成路与方元路交叉口为例，以录像观测法和实地调查法分析该交叉口的交通流特性，运用VISSIM软件建模仿真，进行模型验证。研究结果表明，与原交叉口相比，优化后的交叉口实现了交通流的时空分离，提升了运行效率，研究成果可作为平面交叉口优化设计的参考依据。

As the change of the traffic environment, the design of level intersections on some urban roads can no longer meet the current traffic situation, which cannot withstand the current traffic flow load, making the operation efficiency of the intersections low. Based on the optimization theory and the design guidelines of intersections on urban roads, the optimal signal period was screened, the optimal optimization scheme was matched, and the road traffic capacity model of intersections was established, through the optimal quantitative analysis on the traffic capacity, saturation and service level of intersections. Taking the intersection of Jingcheng Road and Fangyuan Road in Chengdu as an example, the traffic flow characteristics of the intersection were analyzed by video observation method and field investigation method, and the model was verified with VISSIM software. The research results show that compared with the original intersection, the optimized intersection can separate the traffic flow in time and space, to improve the operation efficiency. The research results can be used as a reference for the optimal design of level intersections.